1. Field of the Invention
The present invention relates to an earthquake control operation system for an elevator for allowing passengers in an elevator installed in a building to get off promptly in the event of an earthquake, and more particularly, to an earthquake control operation system for an elevator for ensuring the safety of passengers before an earthquake strikes the elevator and for minimizing the damage caused to its components.
2. Description of the Related Art
A conventional earthquake control operation system for an elevator is provided with a P-wave earthquake sensor for detecting a preliminary tremor of an earthquake or an S-wave earthquake sensor for detecting a principal motion of an earthquake, and performs a control operation. That is, the conventional earthquake control operation system stops the elevator at the nearest floor when the earthquake sensor is operated, or brings the elevator to a sudden halt when an earthquake of a high seismic intensity is detected by the S-wave earthquake sensor.
In one known earthquake control operation system for an elevator as described above, operation information of earthquake sensors is transferred from a building to a management station. A control command is delivered from the management station as for the elevator to perform a control operation. As a result, the number of earthquake sensors can be reduced, and an earthquake control operation can be performed reliably (e.g., see JP 2002-46953 A).
In another known earthquake control operation system for an elevator, the operating states of earthquake sensors installed in various spots of the country are delivered via the Internet and information on an earthquake is thereby acquired in advance instead of performing an earthquake control operation in response to the operation of an earthquake sensor installed in a building. As a result, passengers are allowed to get off a car of the elevator at a safety floor or the nearest floor before the arrival of earthquake waves (e.g., see JP 2004-284758 A and JP 2004-224469 A).
In the conventional earthquake control operation system for the elevator, the earthquake control operation is performed after the earthquake sensor has been operated, so the elevator must be moved even when the occurrence of an earthquake motion has caused a collision of components in a hoistway or strong vibrations of a rope. In many cases, therefore, the components in the hoistway and a rail are damaged.
In the earthquake control operation system in which information on an earthquake is delivered via the Internet, an operation of stopping the elevator at a safety floor is performed if the elevator can be stopped at the safety floor when the information on the earthquake has been received, so the elevator is caused to travel toward the safety floor through a change of direction even when it is traveling away from the safety floor. For this purpose, the car of the elevator needs to be stopped temporarily. Thus, there is a problem in that the car starts traveling again despite temporary stoppage thereof.
In addition, since an attempt to stop the car at the nearest floor is made regardless of whether the car can be stopped at the nearest floor or not, the operation of stopping the car at the nearest floor may not be completed in a situation requiring a long time to stop the car at the nearest floor as in the case of an express zone. As a result, the elevator may still be traveling when the earthquake waves have arrived. This situation causes a problem in that passengers are locked up in the elevator due to sudden stoppage thereof or a restoration is delayed as a result of a damage caused to the components in the hoistway.